OVER THE ARKA-TAGH 
1003 
a winding glen shut in on both sides by subsidiary chains, 
which projected at right angles from the sides of the pass. 
Both chains were shorter than the corresponding spurs on 
the north, their altitudes decreasing rather abruptly, until 
they merged in an undulating level, and finally in an 
extensive tableland. As I gazed southwards across that 
vast high plain, I observed here and there what looked 
like minor irregularities of the surface, intermingled with 
low hills, but in reality they were disconnected portions 
of surviving mountain-chains. The southern horizon was 
edged as far as I could see both east and west by an 
imposing rang'e of dark blue mountains, which however, 
owing to the contrast with the broad plain, appeared to 
be relatively low. Towards the south-east and south-west 
the range was overtopped by peaks and crests covered 
with perpetual snow. To the south-south-west and nearer 
there was a small lake, apparently the gathering-basin for 
the drainage waters of the greater portion of the region 
which lay spread out before us. We had thus reached the 
first basin on the Tibetan plateau not provided with an 
outflow. 
After a good rest on the summit of the pass, we went 
on down its southern side. I was very pleased to know 
that at last I had left behind me East Turkestan, and the 
regions which drain into Lop-nor. We had crossed the 
Kwen-lun Mountains, the Arka-tagh, and the basin which 
stretches between them, and were now treading the 
plateau of Northern Tibet, the vastest upswelling on the 
face of the earth. To the east every inch of the ground 
was unknown territory, except along the route which had 
been followed by Bonvalot and Prince Henry of Orleans, 
and that by which Dutreuil de Rhins and Grenard had 
travelled. In fact the latter must have been near where 
we approached the Tibetan plateau ; but we did not 
observe anything which enabled us to identify it. Little- 
dale’s route we had already left behind us. But we were 
still a long way from the most westerly region that drains 
into the Pacific Ocean, and for a considerable time to 
come we should be travelling in parts which do not con- 
